Mixing or detector circuit arrangement



Aug. 22, 1950 G. DIEMER Er Al.

MIXING 0R DETECTOR CIRCUIT ARRANGEMENT Filed Oct. 20, 1948 PHA $5 Jf//F TEE OSC/L LA TIz Patented Aug. 22, 19750 UNITED STATES PATENT OFFICE MIXING OR DETEGTOR CIRCUIT ARRANGEMENT Conn., as trustee Application October 20, 1948, Serial No. 55,457 inthe Netherlands November-4, 1947 6 Claims.

Thisinvention relates to a circuitarrangement for'producing pulses of short duration and more particularly to a pulse generating circuit arrangement comprising a tube in which an electron beam is produced and in which the deflection of the beam is controlled by a locally generated oscillation.

rEhe principal object of the invention is to provide a circuit arrangement of the above type in which pulses, including high frequency pulses, may be produced in a simple. manner.

Further objects of the invention will appear from the following description.

According to the invention, in a tube of the above type, the electrons impinge on an output system which is arranged in such manner that all, or at least a major part, of the electrons emitted during each cycle of the local oscillations strike the output system substantially simultaneously.

In a preferred embodiment of the invention, the output system is shaped as a helical surface, the axis of the helix coinciding with the axis'of acone generated by the electron beam as it travelsy under the influence of the local oscillations, and the spacing between the endsv of the output systemin the direction of movement of the electrons being substantially equal to the path travelled by an electron during'the cycle of the locally produced oscillation.

In order that the invention may be clearly understood and readily carried into effect it will now be described more fully with reference to the accompanying drawing in which Fig. 1 illustrates one form of a circuit arrangement according to the invention, and

Fig. 2 illustrates another embodiment of a circuit arrangement according to the invention.

Fig. 1 shows a circuit-arrangement according to the invention, comprising a discharge tube in. which the cathode-system substantially consists of the cylindrical electron-emitting member I and a pierced disc 3 which has a positive potential. with respect to the member I and which serves to form the emitted electrons into a beam. The tube further comprises a system of deflection electrodes 4, 5, 6., 'Il which are arranged in pairs, the electrodes of a pair being parallel to each other and the pairs. being perpendicular to each other, a screen 35 and an output system 3|, 32. The electron-beam travels along the axis of. the tube until it reaches the deflection system 4; 5, 6, 'I- by which, it is.` deflected. Voltages having. the frequency of a local oscillator are appliedv` ass control-voltages between the. terminals:-`

I8 connected to the electrodes 4 andr 5. Voltages of the oscillator frequency are also applied between the terminals I9 connected to the electrodes 6 and l, but these voltages are shifted in. phase by with respect to the. voltages: applied to the terminalsl I3. In this manner the beam is caused to define a circular trace, for example in the direction of the arrow, the frequency of rotation being equal tothe local-oscillator frequency.

The output electrode 32 is shaped as a helix having a single turn. The axis of the helix coincides with the axis of thesystem. The helix may be imagined to result from moving a line element along a spiral in such manner that this-line element steadily remains at right angles to the axis of the spiral and remains` directed to this axis, the ends of the turn being spaced apart from one another by a distance. substantially corresponding to the path travelled by an electron during one cycle of the local oscillation.

There may further be provided a grid 35 which has a positive potential and` which serves toY 0btain a suitable configuration of the field` on the right thereof. This field is` preferably an equipotential field. The voltages set up at the electrodes are so chosen that the conical surface generated by the electron beam intersects the anode 3|. It is assumed that the beam travels in the direction of the arrow indicated in the drawing. The pulses obtained are derived from a circuit between the points 33 and 34, which are connected respectively to the output electrode 3l and a grid-shaped electrode 32 which is located in front of the output electrode 3l and shaped similarly thereto. Assuming that, at a given instant, the beam just strikes the left-hand end of the output electrode 3i, then none of the electrons will provisionally be able to reach the anode duringthe further movement. If the spacing of the two ends in the direction of travel of the electrons exactly corresponds toA the path travelled by an electron during one cycle of the local oscillation, the electrons-present at the left-hand end at the starting instant will just reachl the right-hand end when the beam also arrives at this point. An electron present at the plane of the beginning of the helix one half cycle after the starting instant will, in its turn, likewise reach the output electrode one half cycle later, inv other words the output electrode is simultaneously struck by all electrons of the beam emitted during one oscillator-cycle. If the helical output electrode is constructed regularly, the impact takes place in. a very short. time,.so; that in this manner extremely short pulses can be produced with the frequency of the local oscillator.

The arrangement described comprising a helical anode cannot be used for a ilat, tape-shaped electron-beam since the latter is poorly adapted to be deflected by a control voltage in a direction in the plane of the beam. Yet the use of such a beam is often desirable, since it exhibits the a dvantage of being able to convey a greater current With the same thickness and the same voltage, because less trouble is experienced from space charges.

Fig. 2 represents a device according to the invention in which use may be made of a tapeshaped beam in combination with linear deflection by the oscillator voltage at right angles to the plane of the beam.

The arrangement shown in Fig. 2 also comprises a cathode-system l which, in this case,

' emits a tape-shaped electron-beam. The beam traverses the space between the deflection plates 36 and 31 of which the plane extends parallel to the plane of the beam. The oscillator voltage is applied to these deflection plates :and consequently confers on the beam a deflection at right angles to its plane in accordance With the instantaneous values of the oscillator voltage. The

' beam travelling at right angles to its plane in' accordance with the oscillator-voltage may again be caused to traverse a positively charged grid 535. In this case the output electrode 38 is of a special shape and is, more particularly, curved in such manner that the lines of intersection with planes at right angles to the electron beam substantially exhibit the form of a half cosine curve, the sections with planes parallel to the plane of the beam being substantially straight. Furthermore,

the curvature of the anode 38 is such that thel difference in transit time of the electrons pass- -ing to the lower end and of the electrons passing Assuming furthermore that the oscillator volt-` age also varies practically sinusoidally With the time and the size of the anode and the value of the voltages are such that the beam changes its direction to the lower end. of the anode into a direction to the upper end of the anode during one half cycle of the local oscillation, all electrons emitted during one half cycleA of the oscillatoroscillation Will strike the anode simultaneously. In contradistinction to the device shown in Fig. 1, the electrons emitted during the other half cycle of the local oscillation are not utilised.

The pulses produced by the aforesaid circuitarrangement may be used for various purposes, vfor example for mixing with ultra-high fre-i' quency oscillations and frequency-multiplication.

What we claim is:` l. A pulse generator circuit arrangement, comprising a source of oscillations having a given frequency, an electron discharge tube comprising means to `form an electron beam and to -direct said beam along a given path, deflecting means arranged about said path, means to apply said i oscillations to said deflecting means to cause said beam to denne a circular trace and an anode elec-A 4 trode comprising a helically shaped surface having a single convolution about a central axis coinciding with said path, said electrons having a given component of velocity along said path, said convolution having a given pitch substantially equal to the distance travelled by the electrons of said beam during a cycle of said oscillations, and means to derive from said anode the energy imparted thereto by said electron beam.

' 2. A pulse generator circuit arrangement, comprising a source of oscillations having a given frequency, an electron discharge tube comprising means to form an electron beam and to direct said beam along a given path, a plurality of deflecting electrodes arranged about said path, means to apply said oscillations to said deflecting electrodes to cause' said beam to denne a circular trace and an anode electrode comprising a helically shaped surface having a single convolution about a central axis coinciding with said path, said electrons having a given component of velocity along said path, said convolution having a given pitch substantially equal to the distance travelled by the electrons of said beam during a cycle of said oscillations, and means to derive from said anode the energy imparted thereto by said electron beam.

3. A pulse generator circuit arrangement, comprising a source of local oscillations having a given frequency, phase shifting means coupled to said source to produce phase shifted oscillations, an electron discharge tube comprising means to form an electron beam and to direct said beam along a given path, a pair of horizontal deflecting electrodes arranged about said path, a pair of vertical deecting electrodes arranged about said path, means to apply said local oscillations to one of said pairs of deflecting electrodes and said phase shifted oscillations to the other pair of deilecting electrodesto cause said beam to denne a circular trace and an anode electrode comprising a helically shaped surface having a single convolution about a central axis coinciding With said path, said electrons having a given component of velocity along said path, said convolution having a given pitch substantially equal to the distance travelled by the electrons of said beam during a cycle of said local oscillations, and means to derive from said anode the energy imparted thereto bysaid electron beam.

4. A pulse generator circuit arrangement, comprising a source of oscillations having a given frequency, an electron discharge tube comprising means to form an electron beam and to direct said beam along a given path, a plurality of deflecting electrodes arranged about said path, means to apply said oscillations to said deflecting electrodes to cause said beam to define a circular trace, an anode electrode comprising a helically shaped surface having a single convolution about a central axis coinciding With said path and a grid electrode having a shape similar to the shape of said anode interposed between said anode and said deflecting electrodes, said electrons having a given componentof velocity along said path, said convolution having a given pitch substantially equal to. the distance travelled by the ele'ctrons of said beam during a cycle of said oscillations, and means to derive from said anode and electrical pulses having a given periodicity, comprising means to form an electron beam and to .'75 direct said beam along a given path with a given velocity, deecting means arranged about said path, and adapted to cause said beam to define a circular trace, and an anode electrode comprising a helically shaped surface having a single convolution about a central axis coinciding with said path, said convolution having a pitch substantially equal to the distance travelled by the electrons of said b eam during a period of said pulses.

6. An electron discharge tube for producing electrical pulses having a given periodicity, comprising means to form an electron beam and to direct said beam along a given path with a given velocity, a plurality of deecting electrodes arranged about said path and adapted to cause said 1 beam to define a circular trace, an anode electrode comprising a helically shaped surface having a single convolution about a central axis coinciding with said path, said convolution having a pitch substantially equal to the distance travelled by the electrons of said beam during a period of said pulses, and a grid electrode having a shape similar to the shape of said anode interposed between said anode and said deflecting electrodes.

GESINUS DIEMER.

KORNELIS SWIER KNOL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 5 Number Name Date 2,275,480 Varian et al. Mar. 10, 1942 Y' 2,288,694 Fry July 7, 1942 2,374,666 Cunnil May l, 1945 

